Biomedical subjects

G Cividalli

Publications and source records attributed to G Cividalli.

At least 55 records · Page 3Linked to original sources

PubMed1978

Hydrolase activities in normoblasts of beta-thalassemic patients.

A physiological role for glycosidases in cell membranes has been suggested. Therefore the activities of four glycosidases--beta-galactosidase, beta-glucoronidase, N-acetyl-beta-glucosaminidase and acid phosphatase--were examined in normoblasts and membranes of red blood cells (RBC). The enzymatic assays were based on the hydrolysis of fluorimetric 4-methylumbelliferone from the enzyme substrate. In order to avoid contamination by lysosomal activities derived from RBC, the mature RBC and normoblasts obtained from normal controls and thalassemic patients were separated from other blood elements by cellulose chromatography. The cells were disrupted and lysed by freezing and thawing hypotonic solution. Higher enzymatic activities were found in preparations from thalassemic patients than from normal subjects. With a sucrose density gradient, further separation of normoblasts from RBC membranes was obtained, indicating that the normoblast fraction contributed most of the high specific activity found in the thalassemic preparation. It was concluded that relatively high glycosidase activities are present in normoblasts of thalassemic patients. Lower but significant activities were detected in RBC membranes of normal control subjects and thalassemic patients.

Acetylglucosaminidase↗

PubMed1978

Beta O-thalassemia intermedia.

Three patients with a relatively mild form of beta O-thalassemia who did not require regular blood transfusions are described. Globin synthesis was studied by gel filtration and urea-carboxymethylcellulose chromatography of stroma-free hemolysates prepared from peripheral blood and bone marrow cells labeled in vitro with 14C-leucine. gamma/alpha Synthetic ratios in peripheral blood were in the same range as in patients with the severe clinical form of beta O-thalassemia, while gamma/alpha synthetic ratios in bone marrow cells were higher than in that group of patients. The size of the free alpha-chain pool measured in one case was smaller than in other patients with "classical" Cooley anemia. It is concluded that the severity of the clinical course in beta O-thalassemia does not correlate with the imbalance in alpha verus gamma chain synthesis in peripheral blood and is determined by the synthetic ratio in bone marrow cells, where the bulk of hemoglobin synthesis takes place.

Adolescent↗

PubMed1978

Absence of beta mRNA in beta0-thalassemia in Kurdish Jews.

We report the characterization of the amount of beta mRNA in a Kurdish Jewish population with beta0-thalassemia using the same methods employed for characterization of the Catania and Ferrara beta0 patients. We found very low amounts of beta mRNA sequences, consistent with the presence of beta0-thalassemia of the beta mRNA-negative population type. In addition, no globin gene deletion was detected that could account for the absence of beta mRNA.

Adolescent↗

PubMed1978

Absence of functional beta-globin messenger RNA in Kurdish Jews with beta0-thalassemia.

Human globin messenger RNA was isolated from reticulocytes of four Jewish patients of Kurdish origin with homozygous beta0-thalassemia. On translation in the wheat-germ cell-free system, messenger RNA from these patients directed extensive synthesis of alpha- and gamma-globin chains, but synthesis of beta-globin chains was not detectable. In contrast, nonthalassemic human globin messenger RNA directed the synthesis of essentially equimolar amounts of alpha- and beta-globin. The patterns of globin synthesized by beta0-thalassemic messenger RNA in the cell-free system were virtually identical to the patterns of globin synthesized in peripheral blood cells of these patients. beta0-thalassemic messenger RNA similarly failed to direct any detectable beta-globin synthesis in a micrococcal nuclease-treated rabbit reticulocyte lysate, even in the presence of an excess of purified eukaryotic initiation factor 2. These results strongly suggest that functional messenger RNA for beta-globin chains is absent in Kurdish Jews with homozygous beta0-thalassemia.

Cell-Free System↗

PubMed1975

Splenectomy in homozygous beta thalassaemia: a retrospective study of 30 patients.

In order to clarify the indications for splenectomy in patients with homozygous beta thalassaemia we studied, retrospectively, the basal pre-transfusion haemoglobin levels and blood transfusion requirements before and after splenectomy, in a series of patients with this disorder. Thirty-six patients, of whom 20 underwent splenectomy, were included in this study. Three groups of patients with homozygous beta thalassaemia were identified on the basis of clinical and laboratory findings. Two of the three groups consisted of 24 patients with beta thalassaemia major, subdivided retrospectively according to their response to splenectomy. The third group consisted of six patients with beta thalassaemia intermedia who had a comparably mild clinical course. In the first group of 16 patients with beta thalassemia major, monthly transfusions were required from the age of 6 months to 24 months and splenectomy resulted in temporary improvement for a period of 1-2 years. Thereafter, the transfusion requirements returned to pre-operative levels with no sustained improvements in base-line pretransfusion haemoglobin levels. Despite the fact that haematological improvement was temporary, it is felt that splenectomy is indicated in this group since the development and the general well-being of the children was significantly improved. In the second group of eight patients with beta thalassaemia major, transfusion requirements were relatively infrequent before 1-2 years, but after several years the transfusion requirement increased simultaneously with the development of 'hypersplenism'.

Adolescent↗

PubMed1974